Classifications

• • C—CHEMISTRY; METALLURGY
  • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
  • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
  • C23C30/00—Coating with metallic material characterised only by the composition of the metallic material, i.e. not characterised by the coating process
  • C23C30/005—Coating with metallic material characterised only by the composition of the metallic material, i.e. not characterised by the coating process on hard metal substrates
• • C—CHEMISTRY; METALLURGY
  • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
  • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
  • C23C16/00—Chemical coating by decomposition of gaseous compounds, without leaving reaction products of surface material in the coating, i.e. chemical vapour deposition [CVD] processes
  • C23C16/22—Chemical coating by decomposition of gaseous compounds, without leaving reaction products of surface material in the coating, i.e. chemical vapour deposition [CVD] processes characterised by the deposition of inorganic material, other than metallic material
  • C23C16/30—Deposition of compounds, mixtures or solid solutions, e.g. borides, carbides, nitrides
  • C23C16/301—AIII BV compounds, where A is Al, Ga, In or Tl and B is N, P, As, Sb or Bi

Definitions

• This invention relates to a wear-resistant member of cermet, such as a blade member for a cutting tool, having a hard coating which exhibits excellent wear-resistance and toughness.
• a blade member for a cutting tool which comprise a substrate of cermet , such as cemented carbide including tungsten carbide (WC) and titanium carbide- based cermet, and a hard coating formed on a surface of the substrate and comprising one or more layers each composed of one of titanium carbide (TiC), titanium nitride (TiN), carbo-. nitride of titanium (TiCN), oxy-carbide of titanium (TiCO), oxy-nitride of titanium (TiNO) and oxy-carbo-nitride of titanium (TiCNO).
• a coating further comprises an outermost layer of aluminum oxide (Al 2 0 3 ) which is either in the amorphous form or the crystalline form.
• Such a conventional hard coating exhibits excellent wear-resistance, it is inferior in toughness, so that a crack can easily develop in the coating when the coating is subjected to bending stress during the operation of the wear-resistance tool member. In addition, this crack can be transmitted to the substrate of the tool member, so that the resistance of the tool member to breakage or damage is considerably lowered.
• Another object is to provide a process for producing such a surface-coated wear-resistant member.
• a surface-coated wear-resistant member of cermet which comprises a substrate of cermet; and a hard coating vapor-deposited on a surface of the substrate, the coating being composed of at least one titanium compound selected from the group consisting of titanium carbide, titanium nitride, carbo-nitride of titanium, oxy-carbide of titanium, oxy-nitride of titanium and oxy-carbo-nitride of titanium, an atomic ratio of one of carbon, nitrogen, carbon plus nitrogen, carbon plus oxygen, nitrogen plus oxygen and carbon plus nitrogen plus oxygen to titanium(Ti) in the coating being in the range of between 0.3 and 0.8, the coating comprising a compound of TiX and a compound of Ti 2 X wherein X is one of carbon and nitrogen or at least two of carbon, nitrogen and oxygen, and the coating having an average thickness of 1 to 10 ⁇ m.
• a surface-coated wear-resistant member of cermet which comprises a substrate of cermet; and a hard coating vapor-deposited on a surface of the substrate, the coating being composed of titanium metal and at least one titanium compound selected from the group consisting of titanium carbide, titanium nitride, carbo-nitride of titanium, oxy-carbide of titanium, oxy-nitride of titanium and oxy-carbo-nitride of titanium, an atomic ratio-of one of carbon, nitrogen, carbon plus nitrogen, carbon plus oxygen, nitrogen plus oxygen and carbon plus nitrogen plus oxygen to titanium(Ti) in the coating being in the range of between 0.3 and 0.8, the coating comprising titanium metal,a compound of TiX and a compound of Ti 2 X wherein X is one of carbon and nitrogen or at least two of carbon, nitrogen and oxygen, and the coating having an average thickness of 1 to 10 pm.
• a process for producing the above-mentioned surface-coated wear-resistant members is provided.
• the coating of the above-mentioned construction is formed on the surface of the substrate by vapor-depositing at least one layer of titanium metal and at least one layer of titanium compound one upon another, the titanium compound being one of titanium carbide, titanium nitride, carbo-nitride of titanium, oxy-carbide of titanium, oxy-nitride of titanium and oxy-carbo-nitride of titanium.
• the hard coating comprises a compound of TiX and a compound of Ti 2 X wherein X is one of carbon and nitrogen or at least two of carbon, nitrogen and oxygen, TiX and Ti 2 X being hereinafter referred to as "TiC.N.O” and “Ti 2 C.N.O", respectively.
• TiC.N.O titanium
• Ti 2 C.N.O titanium
• the atomic ratio of one of carbon, nitrogen, carbon plus nitrogen, carbon plus oxygen, nitrogen plus oxygen, and carbon plus nitrogen plus oxygen to titanium (hereinafter referred to as "(C + N + 0)/Ti") in the hard coating is in the range of between 0.3 and 0.8.
• the hard coating has a fine structure and has such deformability or toughness as to absorb bending stress applied to the surface-coated wear-resistant member during an operation thereof, thereby preventing a crack from developing in the coating to ensure that the member is not subjected to breakage or damage.
• the hard coating possesses excellent wear-resistance which further enhances the overall wear-resistance of the member.
• the presence of titanium metal in the hard coating will further enhance the toughness of the coating.
• the proportion of Ti 2 C.N.0 to TiC.N.O or the proportion of Ti 2 C.N.O plus titanium metal to TiC.N.O becomes too small, so that the coating fails to possess the required deformability (toughness) to absorb the bending stress applied to the hard coating during the operation of the surface-coated wear-resistant member.
• the hard coating has an average thickness of I to 10 pm. If this thickness is less than 1 ⁇ m, the required toughness of the coating can not be achieved. On the other hand, if the thickness is more than 10 um, the toughness of the coating is also lowered.
• the hard coating is vapor-deposited on the surface of the substrate of the member by chemical vapor deposition, a low-temperature chemical vapor deposition method using an organic agent, or various physical vapor deposition methods.
• the coating should be vapor-deposited on the substrate at temperatures of 600 to 1,000°C.
• the hard coating comprises either TiC.N.O and Ti 2 C.N.0 or TiC.N.O, Ti2C.N.O and titanium metal
• alternate layers of TiC.N.O and Ti 2 C.N.0 can be vapor-deposited on the substrate surface.
• alternate layers of titanium metal and TiC.N.O can be vapor-deposited on the substrate surface, so that the compound of Ti 2 C.N.0 is formed by diffusion between each adjacent layers.
• the hard coating may have an outermost layer of A1 2 0 3 to further enhance its wear-resistance.
• a drawing die which was made of sintered cemented carbide which contained, apart from impurities, 12 % by weight of Co and balance WC, the substrate having a hole extending therethrough for passing a material to be drawn therethrough.
• seven layers of T i metal each having an average thickness of 0.15 pm and seven layers of TiN each having an average thickness of 0.3pm were alternately vapor-deposited one upon another at a temperature of 800°C.by an ion-plating method to form a hard coating of a laminated construction on the surface of the hole of the drawing die to provide a surface-coated wear-resistant drawing die of the present invention, the coating having an average thickness of about 3 ⁇ m.
• a comparative drawing die of the conventional type was also prepared according to the above procedure except that a hard coating was composed of TiN, the coating having an average thickness of about 3 ⁇ m.
• the atomic ratio of N to Ti was 0.65, and it was confirmed by X-ray diffraction that the hard coating contained both TiN and Ti 2 N.
• the drawing die of the present invention had a transverse rupture strength of 290 kg/mm2 while the comparative drawing die had a transverse rupture strength of 210 kg/mm 2 because the toughness of the coating was lower.
• the drawing die of the present invention and the comparative drawing die were used for drawing a stainless steel wire having a diameter of 2 mm at a reduction rate of 15 %.
• the drawing die of the present invention became ineffective when it produced 3,000 m of drawn steel wire.
• the comparative drawing die became ineffective when it produced only 1,000 m of drawn steel wire.
• the service life of the drawing die of the present invention was substantially longer than that of the comparative drawing die.
• a throw-away blade member or insert made of a sintered cermet containing, apart from impurities, 9 % by weight of Co, 10 % of TiC, 10 % of TaC and balance WC.
• six layers of Ti metal each having an average thickness of 0.2 pm and six layers of TiN each having an average thickness of 0.3 ⁇ m were alternately vapor-deposited one upon another at a temperature of 650°C by an ion-plating method to form a hard coating of a laminated construction on a surface of the substrate to produce a surface-coated blade member A of the present invention, the coating having an average thickness of about 3 ⁇ m.
• a layer of A1 2 0 3 having an average thickness of 1 pm was vapor-deposited on the coating of the blade member A by a plasma chemical vapor deposition method to produce a surface-coated blade member B of the present invention.
• each of the blade members A and B the atomic ratio of N to Ti was 0.55. It was confirmed by X-ray diffraction that each coating contained TiN, Ti 2 N and Ti'metal.
• a comparative blade member of the conventional type was also prepared according to the procedure except that a coating was composed of TiN, the coating having an average thickness of about 3 ⁇ m.
• the blade members A and B of the present invention and the comparative blade member were subjected to a continuous cutting test in a lathe.
• the conditions for this continuous cutting test were as follows:
• each blade member attached to a blade holder was used to continuously turn the workpiece to determine how long it took for the flank of the blade member to be worn 0.3 mm.
• the intermittent cutting test it was determined how many blade members of the same construction out of ten were subjected to chipping.
• the blade member A of the present invention exhibited substantially the same wear-resistance as the comparative blade member, and the blade member B of the present invention was much superior in wear-resistance to the comparative blade member. None of the tested blade members A was subjected to chipping, and only one of the tested blade members B was subjected to chipping. On the other hand, nine of the tested comparative blade members were subjected to chipping. Thus, the hard coating of each of the blade members A and B exhibited much more toughness than that of the comparative blade member, and therefore achieved a higher cutting performance in the intermittent steel cutting test in which a substantial bending stress was exerted on the tested blade members.
• a cold-forging die for forming a cross-shaped slot in a screw head which die was made of cemented carbide containing, apart from impurities, 20 % by weight of Co and balance WC. Then, three layers of Ti metal each having an average thickness of 0.12 pm and three layers of TiC 0.2 N 0.6 O 0.2 each having an average thickness of 0.3 ⁇ m were alternately vapor-deposited one upon another at a temperature of 700°C by an ion-plating method to form a hard coating of a laminated construction on a surface of the substrate to produce a surface-coated cold-forging die, the coating having an average thickness of about 1.3 ⁇ m.
• the atomic ratio of C plus N plus O (C + N + O) to Ti was 0.7, and it was confirmed that the coating contained TiCON, Ti 2 N and Ti.
• a comparative forging die of the conventional type was prepared according to the above procedure except that a coating was made of TiC 0.2 N 0.6 O 0.2
• the cold-forging die of the present invention could process 200,000 screws (JIS.S55C) to form a cross-shaped slot in the head of each screw by cold forging before the cold forging die became ineffective.
• the comparative die could only process 50,000 screws before it became ineffective.
• the cold-forging die of the present invention had a substantially longer service life than the comparative die.
• a throw-away blade member or insert made of a sintered cermet containing, apart from impurities, 5 % by weight of Co, 10 % of Ni, 10 % of Mo, 20 % of TiN and balance WC. Then, five layers of Ti metal each having an average thickness of 0.2 um and five layers of TiC 0.3 N 0.7 each having an average thickness of 0.4 ⁇ m were alternately vapor-deposited one upon another at a temperature of 900°C by a sputtering method to form a hard coating of a laminated construction to produce a surface-coated blade member of the present invention, the coating having an average thickness of about 3 ⁇ m.
• the atomic ratio of C plus N (C + N) to Ti was 0.65, and it was confirmed that the coating contained TiCN and Ti 2 CN.
• a comparative blade member was also prepared according to the above procedure except that a coating was made of TiC 0.3 N 0.7
• the surface-coated blade member of the present invention and the comparative blade member were subjected to a turning test.
• the conditions for this turning test were as follows:

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• Chemical & Material Sciences (AREA)
• Mechanical Engineering (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Engineering & Computer Science (AREA)
• Materials Engineering (AREA)
• Metallurgy (AREA)
• Organic Chemistry (AREA)
• General Chemical & Material Sciences (AREA)
• Inorganic Chemistry (AREA)
• Physical Vapour Deposition (AREA)
• Cutting Tools, Boring Holders, And Turrets (AREA)
• Chemical Vapour Deposition (AREA)
• Other Surface Treatments For Metallic Materials (AREA)

Applications Claiming Priority (2)

Publications (4)

Family

ID=16370777

Family Applications (1)

Country Status (4)

Cited By (12)

Families Citing this family (11)

Family Cites Families (8)

• 1983
  • 1983-10-21 JP JP58197217A patent/JPS6089574A/ja active Granted
• 1984
  • 1984-10-18 DE DE8484112566T patent/DE3481009D1/de not_active Expired - Lifetime
  • 1984-10-18 EP EP84112566A patent/EP0149024B2/de not_active Expired - Lifetime
• 1986
  • 1986-09-23 US US06/910,834 patent/US4693944A/en not_active Expired - Lifetime

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